I’m planning to use Multisite to host 200 different wordpress blog with each having their own unique subdomain. I notice each time I create a virtual host for each subdomain it’ll use roughly 50mb ram. So if 50mb * 200 sites = 10GB RAM correct me if wrong is 10GB of RAM needed to host 200 sites? if possible is there solutions to decrease ram usage?
Memory needed to host 200 wordpress sites?
The actual RAM you need depends on many factors:
In a multisite, some resources are shared, the server setup for example is not duplicated each time you create a new site.
You can save some resources if you enable the built-in Opcache, check your theme and the plugins with Xdebug. There is not much you can do with translations.
The number of sites is unrelated to the amount of memory required. The amount of required memory is (if you are using Apache)
the amount of memory required to serve the most memory intensive page * the number of requests you want to serve simultaneouslyBoth numbers vary based on the way you set your server and the themes and plugins you use.
Regarding the memory usage of translations (I’d have commented toschos answer, but I’m lacking the needed reputation): That can be reduced using my plugin WP Performance Pack. It offers use of native gettext if available and an alternative MO implementation (if gettext isn’t available), which only loads used translations. Both methods reduce memory consumption and improve performance of localized WordPress installations.